14 julho 2007

Ice? Just Say "No"

Por Peter Russel

Americans take ice for granted. They expect it in a glass of water at every restaurant. They want it in every soft drink. Most produce a continual supply of it at home in their refrigerators. And for parties we go and buy bags of it to fill up our buckets and bathtubs. But at what cost?Estimating how much ice we consume each day is not easy. In addition to the ice we melt in our drinks and ice buckets, there is all the ice that is produced, only to melt away, unused, in the drain. As a rough guess we probably each "consume", either directly or indirectly, an average of around a pint of water a day as ice.

Ice as a commodity is basically energy, or, more accurately, the absence of it. To freeze water, energy (latent heat) must be extracted from it. When the ice melts, it sucks this energy back, cooling its immediate surroundings.

The latent heat of ice is about 300 joules per gram. (I shall use approximate figures throughout; it makes the calculations easier, and there is no point in using more accurate figures when the amount of ice consumed is only a guess). A pint of water weighs around 450 grams, so the energy consumed in ice by each of us, each day, is around 135,000. There are around 270 million people in the USA, making the national daily energy consumption in ice around 36 trillion joules.

Most of us have no idea how much a joule of energy is, so let us convert this figure to a more meangingful unit, the kilowatt-hour (kWh) which is the amount of energy a one kilowatt electric fire consumes in one hour. One watt is one joule/sec; so a kilowatt-hour is 1,000 x 60 x 60 joules, i.e. 3.6 million joules. Thus our national daily ice consumption represents around 10 million kWh of energy.

To generate this amount of energy takes 5,000 tons of coal, or 17,000 barrels of oil. Here's the rub. We are trying to conserve the energy we use in heating fuel, gasoline and electricity, yet at the same we are melting away a vast quantity of energy as ice -- the energy that a city the size of San Francisco consumes in gasoline each day.

Not only does the production of ice contribute to the energy crisis, it also contributes (somewhat ironically) to global warming. Each kilowatt of energy generated produces about 1.5 lb of carbon dioxide. Our daily ice consumption thus releases an additional 7,000 tons of carbon dioxide into the atmosphere each day, making its own contribution to the greenhouse effect. In addition, we must factor in the cost of the equipment used to produce the ice, plus the damaging effect on the ozone layer of all the CFCs released into the atmosphere when our ice-making machines fall apart on the scrap heap.

Why do we want all this ice? We certainly do not need it. Europeans do not expect it in every glass of water or soft drink, while traditional Japanese, Chinese and Indian medecines advocate the drinkiing of warm water with meals. Its cooling effect on the body is negligible. It has no health benefit. Just the opposite. The temperature stress on our teeth can crack the enamel, increasing the likelihood of tooth decay. The lining of the stomach is weakened by having to cope temperatures for which it was not designed. The cooling in the stomach unnecessarily draws blood from other regions of the body. It also soldiifies the oily stuff in food you have just consumed, which increases the amount of fat absorbed the intestine. In addition, ice-making machines can harbor Legionnaire's Disease and other unsavory microbes. You may drink bottled water, but the chances are the ice that's put in it is tap water.

Ice is a social addiction. We don't need it, but we've been led to believe we can't do without it. Yet we get nothing from it but an oral stimulation.

But every addiction has its cost. Here the cost is unnecessary energy consumption, increased environmental degradation, and possible damage to your health. So the next time you are offered ice, just say "No".

We are people and so, nothing better than ourselves to show that companies and institutions are formed by us, people.

And so we are also, those who will recriate the gigantic wheel-of-life, capable to run and run without attacking or destroying the roads that join our cities, our villages and our people.

We are called to be co-creators of the Universe. We do not wait the stars to fall over our heads, erasing our minds and breaking our hearts. We know to look high, we know the responsibilities, as well as we know to hug Horizons.